#include <bits/stdc++.h>
using namespace std;

int day[13]={-1,31,28,31,30,31,30,31,31,30,31,30,31};

signed main(){
    int ans=0;
    for(int i=1;i<=12;i++){
        for(int j=1;j<=day[i];j++){
            if(i==j%10+j/10)ans++;
        }
    }
    cout<<ans<<endl;
}